on Fedora 17 on my brand new asus, each time I start a new session (restart or after shutdown) it automatically sets brightness back to 100% ... I have to set it back manually... it seems to happen on some other Linux (suse) and some older Fedora too. But I couldn't find a way to correct it.

Another problem is the time that gains 2 hours more after reboot...

(Until recently I was using Fedora 16 on an older computer and never had such pb)

on Fedora 17 on my brand new asus, each time I start a new session (restart or after shutdown) it automatically sets brightness back to 100% ... I have to set it back manually... it seems to happen on some other Linux (suse) and some older Fedora too. But I couldn't find a way to correct it.

Another problem is the time that gains 2 hours more after reboot...

(Until recently I was using Fedora 16 on an older computer and never had such pb)

If I modify the brightness with the GUI tool it will modify (let's say I put it to 8):
/sys/class/backlight/acpi_video1/actual_brightness
/sys/class/backlight/acpi_video1/brightness

If I do 'echo 3 > /sys/class/backlight/acpi_video0/brightness' it will modify the screen brightness.
Both
/sys/class/backlight/acpi_video0/actual_brightness
/sys/class/backlight/acpi_video0/brightness
will be at 3.

However
/sys/class/backlight/acpi_video1/actual_brightness
/sys/class/backlight/acpi_video1/brightness
will still be at 8

Then, as soon as I open the GUI tool it will set the brightness back to the value stored in /sys/class/backlight/acpi_video1/brightness

Now, I see that I can play with this settings to get the brightness I want.

But what I want is that each time my computer restart or reboot it keeps the brightness I set before stoping it.

Hi, I am too interested that system simply *restore* brightness that was in use just before shutdown, restart or suspend.
Seems, it is not working at least in Fedora 17 but I suspect problem occurs in other distributions too.

This is clearly a bug or regression as I see this on my notebook (radeon card inside) where I have
dell_backlight and radeon_bl dirs in /sys/class/backlight and also on friend's toshiba nb-100 netbook (intel atom nm10 graphics) and an asus n53 with intel hd graphics.

Looking for a solution I have stumbled upon something that tell me that gnome-settings daemon is responsible for this and probably the candidate for a new bug report if this one is not enough:https://bugzilla.redhat.com/show_bug.cgi?id=817782
as this one seems corner case.

However some people suggest that we should run gnome-session-properties and in Options tab check "Automatically remember running applications when logging out" but I haven't tried it yet but will

So, solution in post #2 just set fixed brightness value and that's all it does - and is indeed usefull when problems are bigger eg. after reboot some panels are set to minimal brightness due to some other (kernel) bug.

I've spent some time and checked the problem on other versions and distros. Here are the results.

Looks like this issue is Fedora-specific. On my laptop it appears only after F17 update. On fresh installation backlight control works fine. It's also neither kernel nor KDE (I'm a KDE user) issue for I've installed their updates step by step and they do not cause any problems.

Then I've tried openSUSE with the same kernel version and KDE 4.8.5, and its eberything ok on this distro.